| Value | Category | Cases | |
|---|---|---|---|
| -9 | NIU (not in universe) | 2135 |
75.7%
|
| 1 | easy to use method | 206 |
7.3%
|
| 2 | hard to use method | 78 |
2.8%
|
| 98 | don't know | 1 |
0%
|
| 9999995 | missing:impute | 401 |
14.2%
|
| Sysmiss | 1 |